With WaterRoof you can set up the IPFW built-in firewall easily and quickly. With the NAT Setup feature you can fine-tune your Internet sharing for the home LAN, or you can also set up a full-featured dual-homed firewall for your network.Rules and network option can be stored and loaded at boot time.

WaterRoof is only a frontend so it makes use of system tools: this means that when you have finished configuring/testing your firewall, you can safely delete WaterRoof from your system, without loosing your rules. Bandwidth settings, firewall rules, NAT rules, forwarding, logging and other options will be preserved and activated at boot using launchd, following Apple guidelines.This means that WaterRoof is quite safe because it does not install any strange kernel extension or background daemon. You can also download and check WaterRoof source code, it's open.

WaterRoof can be used to learn how ipfw works: you can use predefined rule sets to test firewall behaviour, or you can use the wizard to start from scratch with a step-by-step configuration.But WaterRoof can also be used to deeply configure a ipfw firewall/router, using every ipfw option including traffic shaping (dummynet queues).

English documentation included. Source code available at my Web site. WaterRoof is freeware and open-source.